/**
 * Copyright (C) 2018-2020
 * All rights reserved, Designed By www.yixiang.co
 * 注意：
 * 本软件为www.yixiang.co开发研制
 */
package co.yixiang.utils;

import cn.hutool.core.util.NumberUtil;

/**
 * @ClassName LocationUtils
 * @Author hupeng <610796224@qq.com>
 * @Date 2020/3/24
 **/
public class LocationUtils {
    private static double EARTH_RADIUS = 6378.137;

    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }

    /**
     * 通过经纬度获取距离(单位：千米)
     * @param lat1
     * @param lng1
     * @param lat2
     * @param lng2
     * @return
     */
    public static double getDistance(double lat1, double lng1, double lat2,
                                     double lng2) {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
                + Math.cos(radLat1) * Math.cos(radLat2)
                * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000d) / 10000d;
        //s = s*1000;
        return NumberUtil.round(s, 2).doubleValue();
        //return s;
    }
}
